Instruments or systems for performing diagnostic tests or other processes on patient samples, such as molecular diagnostic tests, commonly employ barcode technology to encode a patient or sample ID (also called an accession ID) to track a sample throughout a laboratory facility. A barcode is placed on a device associated with the sample, such, as a test tube, cuvette, bottle or other container, a slide, a multi-chamber integrated test cartridge, or other device. In some cases the device is disposable and is discarded after the test procedure is complete and the results are recorded. The barcode is manually scanned or is read by a fixed scanner on the instrument before or after the device is placed into the instrument, thereby providing an association between the information encoded in the barcode and the contents of the device. For obvious reasons, it is critical that the association between the information encoded in the barcode and the contents of the device be accurate. That is, if the device contains a patient sample, it is critical that the information encoded in the barcode on that device identify the correct patient.
When a barcode, or other scannable ID tag, is scanned outside an instrument before placing the device in the instrument, the association between the contents of the device and the information encoded in a barcode is created outside the instrument, and that association may apply throughout the processing operation. For example, when an instrument has a number of distinct processing locations in which a device may be placed for processing, the user may select an available processing location or the instrument may instruct the user which processing location to use next. In this case, the association between the ID information and the device contents for a particular processing location is created before the device is placed in that processing location. For example, if the use selects or is instructed to next load processing location “six” and then scan an ID for “patient B”, the instrument will be expecting patient B's sample in processing location six, and the results of the test that is performed in processing location six will be associated with patient B. Thus, a problem is created if, after creating the association between processing location six and patient B, a device containing another patient's sample, “patient C,” is placed in processing location six.
Often when a diagnostic instrument is being prepared for operation by laboratory personnel, there are multiple sample devices that must be loaded into the instrument, each device with its own unique accession ID or barcode. If the laboratory personnel scans the ID code of a first device, i.e., “device A,” and then mistakenly loads a different device, i.e., “device B,” into the instrument, the instrument will incorrectly associate the results of tests performed on patient B's sample to patient A.